Enhanced N channel FET with no inherent diode to V
CC
5Ω bidirectional switches connect inputs to outputs
Ω
Zero propagation delay
Zero ground bounce
Undershoot clamp diodes on all switch and control pins
Four enables control five bits each
TTL-compatible input and output levels
Available in 48-pin QVSOP package
DESCRIPTION:
The QS32X384 provides a set of twenty high-speed CMOS TTL-
compatible bus switches. The low ON resistance of the QS32X384 allows
inputs to be connected to outputs without adding propagation delay and
without generating additional ground bounce noise. The Bus Enable (BE)
signals turn the switches on. Four Bus Enable signals are provided, one
for each of five bits of the 20-bit bus. The ‘384 family of QuickSwitch products
is ideal for switching wide digital buses, as well as hotplug buffering, and 5V
to 3V conversion.
The QS32X384 is characterized for operation at -40°C to +85°C.
APPLICATIONS:
•
•
•
•
•
•
Hot-swapping, hot-docking
Voltage translation (5V to 3.3V)
Power conservation
Capacitance reduction and isolation
Bus isolation
Clock gating
FUNCTIONAL BLOCK DIAGRAM
A
0
B
0
A
10
B
10
A
4
A
5
B
4
B
5
A
14
A
15
B
14
B
15
A
9
B
9
A
19
B
19
BEA
BEC
BED
BEB
The IDT logo is a registered trademark of Integrated Device Technology, Inc.
INDUSTRIAL TEMPERATURE RANGE
c
2002 Integrated Device Technology, Inc.
APRIL 2002
1
DSC-5729/1
IDTQS32X384
HIGH-SPEED CMOS 20-BIT BUS SWITCH
INDUSTRIAL TEMPERATURE RANGE
PIN CONFIGURATION
BEA
B
0
A
0
A
1
B
1
B
2
A
2
A
3
B
3
B
4
A
4
GND
BEC
B
5
A
5
A
6
B
6
B
7
A
7
A
8
B
8
B
9
A
9
GND
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
QVSOP
TOP VIEW
ABSOLUTE MAXIMUM RATINGS
(1)
Symbol
Description
Max
–0.5 to +7
–0.5 to +7
–0.5 to +7
–3
120
0.5
–65 to +150
Unit
V
V
V
V
mA
W
°C
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
V
CC
B
19
A
19
A
18
B
18
B
17
A
17
A
16
B
16
B
15
A
15
BEB
V
CC
B
14
A
14
A
13
B
13
B
12
A
12
A
11
B
11
B
10
A
10
BED
V
TERM
(2)
Supply Voltage to Ground
V
TERM
(3)
DC Switch Voltage V
S
V
TERM
(3)
DC Input Voltage V
IN
V
AC
I
OUT
P
MAX
T
STG
AC Input Voltage (pulse width
≤20ns)
DC Output Current
Maximum Power Dissipation (T
A
= 85°C)
Storage Temperature
NOTES:
1. Stresses greater than those listed under ABSOLUTE MAXIMUM RATINGS may cause
permanent damage to the device. This is a stress rating only and functional operation
of the device at these or any other conditions above those indicated in the operational
sections of this specification is not implied. Exposure to absolute maximum rating
conditions for extended periods may affect reliability.
2. V
CC
terminals.
3. All terminals except V
CC
.
CAPACITANCE
(T
A
= +25°C, F = 1MHz, V
IN
= 0V, V
OUT
= 0V)
Pins
Control Inputs
Quickswitch Channels (Switch OFF)
NOTE:
1. This parameter is guaranteed but not production tested.
Typ.
3
5
Max.
(1)
5
7
Unit
pF
pF
FUNCTION TABLE
(1)
BEA
H
L
H
L
BEC
H
L
BEB
H
H
L
L
BED
H
H
L
L
B
0
- B
4
Hi-Z
A
0
- A
4
Hi-Z
A
0
- A
4
B
5
- B
9
Hi-Z
A
5
- A
9
Hi-Z
A
5
- A
9
B
15
- B
19
Hi-Z
Hi-Z
A
15
- A
19
A
15
- A
19
B
10
- B
14
Hi-Z
Hi-Z
A
10
- A
14
A
10
- A
14
Function
Disconnect
Connect
Connect
Connect
Function
Disconnect
Connect
Connect
Connect
PIN DESCRIPTION
Pin Names
A
0
- A
19
B
0
- B
19
BEA
BEB
BEC
BED
I/O
I/O
I/O
I
I
I
I
Bus A
Bus B
Enable,
0 - 4
Enable,
15 - 19
Enable,
5 - 9
Enable,
10 - 14
Description
H
L
NOTE:
1. H =
L =
X =
Z =
HIGH Voltage Level
LOW Voltage Level
Don’t care
High-Impedence
2
IDTQS32X384
HIGH-SPEED CMOS 20-BIT BUS SWITCH
INDUSTRIAL TEMPERATURE RANGE
DC ELECTRICAL CHARACTERISTICS OVER OPERATING RANGE
Following Conditions Apply Unless Otherwise Specified:
Industrial: T
A
= –40°C to +85°C, V
CC
= 5V ± 5%
Symbol
V
IH
V
IL
I
IN
I
OZ
R
ON
V
P
Parameter
Input HIGH Voltage
Input LOW Voltage
Input Leakage Current (Control Inputs)
Off-State Current (Hi-Z)
Switch ON Resistance
Pass Voltage
(2)
Test Conditions
Guaranteed Logic HIGH for Control Inputs
Guaranteed Logic LOW for Control Inputs
0V
≤
V
IN
≤
V
CC
0V
≤
V
OUT
≤
V
CC
, Switches OFF
V
CC
= Min, V
IN
= 0V, I
ON
= 30mA
V
CC
= Min, V
IN
= 2.4V, I
ON
= 15mA
V
CC
= 5V, I
OUT
= -5µA
NOTES:
1. Typical values are at V
CC
= 5V and T
A
= 25°C.
2. Pass voltage is guaranteed but not production tested.
Min.
2
—
—
—
—
—
3.7
Typ.
(1)
—
—
±0.01
±0.01
5
10
4
Max.
—
0.8
±1
±1
7
15
4.2
Unit
V
V
µA
µA
Ω
V
TYPICAL ON RESISTANCE vs V
IN
AT V
CC
= 5V
16
R
ON
(ohms)
14
12
10
8
6
4
2
0
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
V
IN
(Volts)
3
IDTQS32X384
HIGH-SPEED CMOS 20-BIT BUS SWITCH
INDUSTRIAL TEMPERATURE RANGE
POWER SUPPLY CHARACTERISTICS
Symbol
I
CCQ
∆I
CC
I
CCD
Parameter
Quiescent Power Supply Current
Power Supply Current per Control Input HIGH
(2)
Dynamic Power Supply Current per MHz
(3)
Test Conditions
(1)
V
CC
= Max., V
IN
= GND or V
CC
, f = 0
V
CC
= Max., V
IN
= 3.4V, f = 0
V
CC
= Max., A and B Pins Open,
Control Input Toggling at 50% Duty Cycle
NOTES:
1. For conditions shown as Min. or Max., use the appropriate values specified under DC Electrical Characteristics.
2. Per TTL driven input (V
IN
= 3.4V, control inputs only). A and B pins do not contribute to
∆Icc.
3. This current applies to the control inputs only and represents the current required to switch internal capacitance at the specified frequency. The A and B inputs generate
no significant AC or DC currents as they transition. This parameter is guaranteed but not production tested.
Max.
3
2.5
0.25
Unit
mA
mA
mA/MHz
T
A
= -40°C to +85°C, V
CC
= 5.0V ± 5%
C
LOAD
= 50pF, R
LOAD
= 500Ω unless otherwise noted.
Symbol
t
PLH
t
PHL
t
PZL
t
PZH
t
PLZ
t
PHZ
Data Propagation Delay
(2,4)
Ax to Bx, Bx to Ax
Switch Turn-on Delay
BEn
to Ax, Bx
Switch Turn-off Delay
(2)
BEn
to Ax, Bx
Parameter
SWITCHING CHARACTERISTICS OVER OPERATING RANGE
Min.
(1)
—
1.5
1.5
Typ.
—
—
—
Max.
0.25
(3)
6.5
5.5
Unit
ns
ns
ns
NOTES:
1. Minimums are guaranteed but not production tested.
2. This parameter is guaranteed but not production tested.
3. The time constant for the switch alone is of the order of 0.25ns for C
L
= 50pF.
4. The bus switch contributes no propagation delay other than the RC delay of the ON resistance of the switch and the load capacitance. Since this time constant is much smaller
than the rise and fall times of typical driving signals, it adds very little propagation delay to the system. Propagation delay of the bus switch, when used in a system, is
determined by the driving circuit on the driving side of the switch and its interaction with the load on the driven side.
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